Seal cap

ABSTRACT

The seal cap of a resilient plastic material and comprises a top, an inner annular skirt which depends from said top and an outer peripheral annular skirt which depends from said top and which is spaced concentrically from said inner annular skirt. The outer annular skirt has a beaded lower edge provided with peripherally spaced apart, radially outwardly directed projections, which are adapted to support the weight of said cap and tend to bend upwardly under the action of a weight which corresponds to the weight of a filled bottle to which the cap is to be applied.

United States Patent 1191 Kaltenhauser et a1.

[ SEAL CAP [21] Appl. No.: 135,831

[30] Foreign Application Priority Data Apr. 30, 1970 Germany 2021372 521 US. c1. ..21s/320, 2 15/ 3 4 1, 215 /15 4 [51] Int. Cl B65121 41/22 [58] Field of Search 215/41, 42, 47; 53/42, 53/329 [56] References Cited UNITED STATES PATENTS 3,549,038 .12/1970 Lohter 215/42 3,231,123 1/1966 l-leierle 215/41 3,343,700 9/1967 Heubl 215/41 3,462,035 8/1969 Grussen 215/41 3,254,785 6/1966 Lovell 215/41 1451 May 7, 1974 3,300,073 1/1967 Benz 215/42 FOREIGN PATENTS OR APPLlCATlONS 1,476,798 3/1967 France 215/42 970,531 9/1964 Great Britain.. 215/41 213,655 5 1956 Australia 215 41 Primary Examiner-William T. Dixson, Jr. Assistant Examiner-Stephen Marcus Attorney, Agent, or Firm-Otto John Munz [57] ABSTRACT tion of a weight which corresponds to the weight of a filled bottle to which the cap is to be applied.

12 Claims, 4 Drawing Figures pATENTEDm 7 m4 I 809-277 INVENTDRS LUDWIG A KALTENHAUSER ALFRED F TSCHUGGNAL l i W ZATTORNEY SEAL CAP This invention relates to a seal cap of a resilient plastic material and serves for the original sealing of bottle having a neck rim bead by means of a cap closing machine, which seal cap comprises an outer annular skirt having a beaded lower edge, which is intended to engage the lower portion of the neck rim bead of the bottle, and an inner annular skirt, which is intended to sealingly engage the inside of the bottleneck;

A bottle'having a neck rim bead is usually sealed with a so-called crown cork made of metal. When the bottle is opened by means of a special tool, the metallic crown cork is permanently deformed so that a bottle which has been opened cannot be subsequently sealed with the same 'cork. Besides, the metallic crown cork must be provided with an insert of cork or plastic material in order to ensure a reliable seal of the filled bottle. A sea] cap made of resilient plastic material has been used in an endeavor to avoid the above-mentioned disadvantages. A seal cap of this type is lighter in weight, may be made in one piece, e.g., by injection molding, and if properly designed may be used to re-seal the bottle when it has been opened.

A seal cap of the kind described first hereinbefore has been described in the Austrian Pat. Specification 245,415. That known seal cap is provided with a beaded lower edge that has such a thickness and a beveled surface so that an opening tool of thekind which is conventional with a metallic crown cork can be applied. l-lence, a bottle thatv has been sealed with the known seal cap is opened in the known manner but without deformation of the resilient seal cap so that the same may be used to re-seal the bottle. The sealing action of the known seal cap is due not only to the outer annular skirt, which is in tight resilient contact with the neck rim bead of the bottle, but also to the inner annular skirt, which is of a greater height than the height of the outer annular skirt and has sealing projections which engage the inside surface of the bottleneck. To facilitate the gripping of that seal cap particularly when it is to be re-applied, the outside surface of the outer annular skirt is knurled or milled. To ensure that the known seal cap is a firm and tight fit on the filled bottle, which in many cases contains a carbonated liquid that has been filled under pressure, the known seal cap must be applied by a machine. The known seal cap of resilient plastic material cannot be applied by a conventional apparatus that applies a metallic crown cork. Such apparatus operates basically as follows:

The filled bottle to be sealed stands on a vertically movable support under a circular opening. A hollowconical press die is disposed over said opening. A sorting device is provided, which produces an air stream by which the metallic crown cork intended for the bottle is carried in the proper orientation to a position over the opening. At that stage, the crown cork still has an outwardly protruding conical rim, which rests on the support around the opening. The bottle is now raised to extend through the opening and to engage the cork and force the same into the conical die, which deforms the crown cork so that the latter conforms to the bottleneck. The bottle now provided with the cork is then lowered through the opening. The diameter of the opening is selected to clear the bottleneck and the crown cork conforming thereto. Because a seal cap of resilient plastic material has the same outside diameter before and after its application to the bottleneck, the

seal cap cannot be supported around the opening. Such sealing apparatus is also unsuitable for applying other known seal caps which are made from resilient plastic material and provided with a rim which can be torn off or torn open by means of projecting tabs and/or noses. Whereas these known seal caps could be supported over the opening by means of these projections, the bottle when sealed as described could not be retracted through the opening.

It is an object of the present invention to provide a seal cap of the kind described first hereinbefore that it can be applied with the existing sealing machines previously used to apply crown corks made of metal.

This object is accomplished according to the present invention in that the lower edge of the outer skirt is provided with spaced apart, outwardly directed projections, which have .such a strength that they can support the weight of the cap itself on an annular supporting surface but tend to bend upwardly under the action of the weight of the filled bottle.

The seal cap according to the present invention can be used in a machine of the type described above. When the cap has been supplied by the sorting device, the projections prevent the cap from falling through the opening. When the cap has been forced onto the bottle, the action of the weight of the filled bottle is sufficient to bend the projections upwardly as the applied cap is moved through the opening so that these projections will not prevent the passage of the cap. The use of the seal cap according to the present invention enables the utilization of the above-described, desirable properties of caps of plastic material whereas it is not necessary to provide new machines or to alter existing machines. This is a considerable economic advantage.

Besides, the pressure which must be applied to the seal caps of plastic material to secure them to the bottle is lower and a lower pressure is also sufficient for blowing the cap into position from the sorting device. Thus, power is saved and also the operation can be performed at a higher speed. The projections may suitably consist of thin, flat lugs, which are highly flexible and have a relatively large engaging surface.

'In a preferred embodiment, the seal cap is provided with lugs having a thickness of about l/ 10 millimeter, a radial length of about 178 millimeter and a maximum width of about 178 millimeter. Hence the projections increase the outside diameter of the seal cap by about 1 millimeter when the cap is supported over the opening whereas the increase is only 1/10 millimeter when the projections have been bent upwardly. Owing to that difierence, the sealed bottle can be lowered through the suitably dimensioned opening.

The lugs may be approximately semicircular so that the rounded end of the lugs facilitates the sliding of the lugs over the rim of the opening in a downward direction.

In another embodiment, the lugs have suitably a largest width at a point which is spaced from the lower edge of the cap and the lugs are narrower at the portion where they are to be bent so that they can be bent more easily whereas their edge portion intended to rest on the support to hold the cap over the opening has a larger width.

The projections are suitably spaced apart by a distance which is twice their largest width. With that arrangement, the retraction of the sealed bottle through the opening will not be braked by an excessive air drag.

It will be economically desirable to injection-mold the projections in one piece with the seal cap. In this case, the provision of the projections increases the manufacturing costs only because of the need to procure an injection-molding die. However, the material expenditure involved in the projections is insignificant compared to the entire cap.

When the closed cap is retracted through the opening, the frictional resistance presented by the bent pro jection results in a small force tending'to lift the cap from the bottle. To compensate for that force, although it is very small, the seal cap according to the present invention maybe provided with means to improve the firm and tight fit of the cap on the bottle. For instance, the top of the cap may initially have an inwardly protruding conical portion within the inner annular skirt. That portion of the top of the cap is forced outwardly under the pressure in the bottle when the cap has been applied thereto. This pressure action increases the contact pressure between the beaded edge of the cap and the bottleneck so that the seal cap has a firmer fit.

The inside surface 'of the outer annular skirt above the edge bead and/or the underside surface of the top of the cap outside of the inner annular skirt may be roughened. That design will ensure a slip-proof fit of the seal 'cap even when the bottleneck is in a moisten condition as a result of cleaning and filling operations. The provision of a rough surface does not add to the manufacturing costs; that surface may be provided in an economical manner by sandblasting the mold for the seal cap in the desired areas.

The seal cap may be provided on its inner annular --skirt with peripheral sealing projections in the form of lips, which extend downwardly and outwardly from the skirt and have a width of about 4/10 millimeter and a thickness of about l/lO millimeter. When the seal cap is applied to the bottleneck by a machine, the lips engage the inside surface of the bottleneck and are bent upwardly, opposite to their inclination, as they are lowered in the bottleneck. As a result, the, lips resiliently bear on the inside surface of the bottle to provide a good seal. This design will also compensate the tolerances which are inevitable with bottlenecks.

During the raisingv of the bottle, a reliable centering of the seal cap relative to the bottle will be ensured if the inner annular skirt is lower than the outer annular skirt.

Because the seal cap according to the present invention is to be applied by the sealing machine which has previously been used for sealing a metallic crown cork, the sorting device associated with such machine may also be used with the present seal cap.

For this reason, a seal cap according to the present invention may have a knurled edge portion on the outside surface of the outer annular skirt and may be designed to have a smooth peripheral surface portion in a height of at least 4 millimeters between the knurled edge portion and the top of the cap. Owing to that smooth edge portion, the conventional sorting device can test whether the seal cap has the correct orientation and can correct the desired orientation of the seal cap when this is required.

Embodiments of the present invention are shown by way of example in the accompanying drawing, in which FIG. 1 is an enlarged bottom view showing a seal cap,

FIG. 2 is a sectional view taken through the inverted I positioned cap on line II-II in FIG. 1,

FIG. 3 is an enlarged view showing a detail of a different embodiment, and

FIG. 4 is a view similar to FIG. 3 and shows a detail of a further embodiment.

The seal cap shown in FIGS. 1. and 2 consists of a single piece of resilient plastic material. The cap has a circular substantially flat top portion or top 1, an outer annular skirt 2 formed on the peripheral of the top and an inner concentrically spaced annular skirt 3, which is of a lesser height than the height of the outer annular skirt 2.

At the seals lower edge, which is shown to be the top in FIG. 2, the outer annular skirt 2 is provided with a bead 4, which engages the lower portion of a neck rim bead of a normally vertically positioned filled bottle (not shown) to which the cap has been applied. Outwardly directed projections 5 protrude from and are spaced apart around the lower edge. These projections are integrally injection-molded with the seal cap and have a thickness a of about 1/10 millimeter, a length b in the radial direction of the cap of about millimeter and a largest width c also of about millimeter. The spacing d of the projections 5 is about twice their largest width. ln the embodiment shown in FIG. 1, the projections are approximately semicircular. Each of the FIGS. 3 and 4 is an enlarged view showing a portion of the lower edge of a different embodiment, in which the projections have a largest width at a point which isv limeters is provided between the knurled edge portion 6 and the top 1 of the cap.

The inner annular wall3 is provided with sealing pro jections 8 in the form of peripheral lips having a width of about 4/10 millimeter and a thickness of l/ 10 millimeter. These lips extend downwardly and outwardly from the skirt 3. In this connection, the term downwardly is applicable when the seal cap is in position on the normally vertically positioned filled bottle. FIG. 2 shows the seal cap in an inverted position and indicates the inclination of the sealing projections 8.

The top 1 of the cap has an inwardly and downwardly protruding conical portion la inside of the inner annular skirt. The pressure in a bottle to which the seal cap is applied will force said portion la outwardly.

That portion of the inside surface of the top 1 which is disposed outside of the inner annular skirt 3 and the inside surface of the outer annular skirt 2 is roughened. For this purpose, the mold used to make the cap is sandblasted in the desired areas. The roughening feature has been exaggerated in FIG. 2 for greater clearness.

The invention is not restricted to the embodiments shown by way of example. Specifically, the shape and dimensions of the projections may be varied in dependence on the resiliency of the material which is used and on the nature of the bottles and of the machines used to seal the same. The design of the outside surface of the seal cap may also be modified in adaptation to an existing sorting device.

What is claimed is:

1. An easily removable machine applicable seal cap of resilient plastic material capable of reuse for firmly and tightly sealing liquid in a bottle having a neck rim bead, said cap comprising:

an outer annular skirt having a beaded lower edge;

said outer annular skirt having outwardly directed spaced projecting lugs to support said cap and bend upwardly under pressure, said lugs having greater flexibility than said skirt portion;

the top of the cap having an inwardly protruding conical portion and an inner annular skirt;

said inner annular skirt being roughened and having inclined sealing projections.

2. A cap as set forth in claim 1, in which said projections consist of lugs. v

3. A cap as set forth in claim 2, in which said lugs have a thickness of H10 millimeter.

4. A cap as set forth in claim 2, in which said lugs have a radial length of /fi millimeter.

5. A cap as set forth in claim 2, in which said lugs have a thickness of l l millimeter and a radial length of /2 millimeter 6. A cap as set forth in claim 5, in which said lugs have a largest width of 7% millimeter.

7. A cap as set forth in claim 2, in which said lugs are approximately semicircular.

8. A cap as set forth in claim 1, which is an integral injection molding.

9. A cap as set forth in claim 1, in which said outer annular skirt has a roughened surface portion above said beaded lower edge.

10. A cap as set forth in claim 1, in which said top portion has a roughened underside surface portion outside said inner annular skirt and inside said outer annular skirt.

11. A cap as set forth in claim 1, in which said inner annular skirt is provided on its outside surface with peripheral sealing lips extending downwardly and outwardly from said inner annular skirt and having a radial width of about 4/10 millimeter and a thickness of about 1/10 millimeter.

12. A cap as set forth in claim 1, in which said outer annular skirt is formed with a knurled outside surface portion adjacent to said beaded lower edge and with a smooth surface portion having a height of at least'4 millimeters and disposed between said knurled surface portion and said top portion. 

1. An easily removable machine applicable seal cap of resilient plastic material capable of reuse for firmly and tightly sealing liquid in a bottle having a neck rim bead, said cap comprising: an outer annular skirt having a beaded lower edge; said outer annular skirt having outwardly directed spaced projecting lugs to support said cap and bend upwardly under pressure, said lugs having greater flexibility than said skirt portion; the top of the cap having an inwardly protruding conical portion and an inner annular skirt; said inner annular skirt Being roughened and having inclined sealing projections.
 2. A cap as set forth in claim 1, in which said projections consist of lugs.
 3. A cap as set forth in claim 2, in which said lugs have a thickness of 1/10 millimeter.
 4. A cap as set forth in claim 2, in which said lugs have a radial length of 1/2 millimeter.
 5. A cap as set forth in claim 2, in which said lugs have a thickness of 1/10 millimeter and a radial length of 1/2 millimeter
 6. A cap as set forth in claim 5, in which said lugs have a largest width of 1/2 millimeter.
 7. A cap as set forth in claim 2, in which said lugs are approximately semicircular.
 8. A cap as set forth in claim 1, which is an integral injection molding.
 9. A cap as set forth in claim 1, in which said outer annular skirt has a roughened surface portion above said beaded lower edge.
 10. A cap as set forth in claim 1, in which said top portion has a roughened underside surface portion outside said inner annular skirt and inside said outer annular skirt.
 11. A cap as set forth in claim 1, in which said inner annular skirt is provided on its outside surface with peripheral sealing lips extending downwardly and outwardly from said inner annular skirt and having a radial width of about 4/10 millimeter and a thickness of about 1/10 millimeter.
 12. A cap as set forth in claim 1, in which said outer annular skirt is formed with a knurled outside surface portion adjacent to said beaded lower edge and with a smooth surface portion having a height of at least 4 millimeters and disposed between said knurled surface portion and said top portion. 